The goal of this project is to analyze the developmental regulation of nyelin basic protein (MBO) synthesis and assembly innormal and mutant mouse brain and in culture in order to elucidate the relationship between MPB polymorphism and myelin morphogenesis. We will use in vitro translation of mRNA, immunoprecipitation withmonoclonal antibody gel electrophoresis, and tryptic fingerprinting to study MBP synthesis. We will use subcellular fractionation, immunoblotting with monoclonal antibody, in vitro assembly, and immunocytochemistry to study the assembly of MBP into myelin. The results will yield new information concerning the molecular mechanisms of MBP gene experssion and myelin morphogenesis. Specifically we will determine what regulated the proportions of individual forms of MBP that accumulate in myelin. This will provide imprtant insight into the developmental biology of the nervous system and will also aid in the understanding of diseases such as multiple sclerosis that affect either myelin or the process of myelin formation. The results may also shed light on the process of myelin repair of remyelination after CNS injury of demyelinating disease. The experiments on MBP synthesis and assembly in the jimpy and shiverer mutant mice will provide useful models for understanding genetic disorders of infectious diseases that affect the process of myelination in children.